There is little information on risk factors for infectious disease mortality in infancy. Data from the NCHS 1987 Linked Birth/Infant Death data set has been analyzed in order to describe infectious disease mortality among U.S. infants as well as to identify potential determinants of infectious disease mortality during three periods: early neonatal, late neonatal, and postneonatal. The potential risk factors under study are derived from information available on birth certificates. Classification of cause of death is based on information listed on infants' death certificates. Hypotheses generated using this data set will be tested in the soon to be released NCHS 1989 Linked Birth/Infant Death data set.